Contributed by Xiaoyan Wang, MD, PhD and Sydney Finkelstein, MD
Published on line in November 2000
The patient is a 75-year-old white male who underwent partial gastrectomy in 1997. The pathologic diagnosis was malignant epithelioid gastrointestinal stromal tumor (GIST). Microscopic sections were not available for histopathology review. The patient had no evidence of recurrent or metastatic disease over the last few years. However, he did have several episodes of presumed retroperitoneal bleeding secondary to his need for anticoagulation for a prosthetic mitral valve. In 09/2000, the patient developed abdominal distension, weakness, and anemia. Further CT scan showed free intra-abdominal blood. He underwent laparoscopy at an outside hospital on 09/14/2000, which confirmed abdominal hemorrhage but showed no obvious source of bleeding. He developed bleeding in the postoperative period and returned to the operating room for exploratory laparotomy 09/15/2000. At that time, several peritoneal implants were noted, and a large unruptured hematoma in the lesser sac was resected. Histopathologic features were consistent with recurrent GIST. Most recently, the patient developed recurrent anemia and abdominal distension. Follow-up imaging revealed an approximately 7 cm mass in the lesser sac with associated blood. He was admitted to UPMC on 10/16/2000 and attempted resection of an apparent recurrent GIST. An exploratory laparotomy revealed multiple tan fleshy nodules present on the peritoneal surfaces, including the small bowel mesentery, the sigmoid mesentery, the pelvic peritoneum and a moderate amount of old blood in the right upper quadrant and in the pelvic region. Frozen section evaluation was consistent with his previous GIST. Soft, fleshy, tan tumor and contained hematoma was noted in the lesser sac, extending to the posterior wall of the stomach, the root of the transverse mesocolon, posterior towards the pancreas and posteroinferiorly towards the duodenum. The tumor was deemed unresectable and debulked intraoperatively for control of bleeding and possible palliation from mass effect. The patient had a relatively uncomplicated postoperative course and was discharged on 10/26/2000.
The specimens were sent in multiple parts including omental, peritoneal, sigmoid colon, pelvic implants and tumor fragments from the lesser sac. Grossly, they were tan fleshy fragments, ranging 0.6 cm to 4.5 cm. The tumor from the lesser sac had soft, fleshy, tan appearance with severe edema, measuring 6.0 x 6.0 x 1.0 cm in aggregate.
MICROSCOPIC DESCRIPTION AND MOLECULAR GENETIC ANALYSIS